Variable condenser



.Q @-@HERPEQK VARIABLE CONDENS ER Filed A1191. 26, 1922 .30 vnomi'cally manufactured,

Patentedv Dec. 23, i924.

UNljrED. STATES CASIMIR S. CEEBPECK, OF CHICAGO, :ILLINOIS VARIABLE CONDENSER.

Application led August 26, 1922. Serial No. 584,590.

To aZZ whom it may concern.'

Be it known that l, CAsrMm S. CHERPECK, a citizen of the `UnitedStates, residing at Chicago, inthe county of Cook and State` of Illinois, have invented certain new and `useful'Improvements in Variable Condensers;` and I do hereby declare the following to be a Jull, clear, and exact description of the invention, such as will enable others skilled in the'fartto which it appertains to make and use `the same.

This invention relates to improvements in electrical condensersi, andhas for one of its main objects the provision of a condenser gadapted for radio work, both for sending and receiving, and whichshall be of a readily variable capacity.

One of the main objects of this invention is the provision of a variable condenser especially adapted for radio work, provided with means whereby the capacity of the same may be varied through quite a wide range, and which variation shall be manually controlled so as to enable the operator to make very 1delicate adjustments for proper tuning and variation 'of wave lengths.

A further important object of this invention is the provision of a variable condenser which will be simple of construction, ecoand which is l,adapted to be used in connection with inductances'whch may' be relatively crude, either connected in series or in parallel therewith, and provided with means making it capable of very fine adjustmf-znt,`

thereby making it serve as the finishing touch for such inductances. Another and further important object of this invention is the provision of a variable 40 condenser'composed of a plurality of plates of metal f'oil or the like, separated by a dielectric of mica or other insulator, aving a portion of the plates hingedly mounted relatively `to the remaining plates, and provided .45 with means whereby the distance between the plates may be readily adjusted, and rendering possible the making of very fine or delicate variations in the capacity of the instrument.

An' important object of this invention is the provisionof a variable condenser which shall be dust-proof, not liable to get out of order, and which can be used in any position desired without impairing its eii'ectiveness. Further, with 'the improved construction of this invention, there is no possibility of the plates contacting, thereby causing short circuits, which practically ruin the condenser, and which often' occurs in the case of the ordinary aluminum air condenser now on the market.

Other and further important objects of the invention will be apparent from the dist closures inthe accompanying drawings and following specification. i

The invention, in a .preferred form, is illustrated in the drawings and hereinafter more fully described.

In the drawings:

Fig. 1 is a vertical sectional lview of the Vimproved device of this invention,

Fig. 2 is a sectional view taken on the line 2-2-of Fig. l, looking in the direction indicated by the arrows.

Fig. 3 is a detail view, enlarged, showing 75 the condenser construction, as illustrated in Fig. 1.

Fig. 4 is a vertical sectional view, showing a modification of the invention. i

Fig. 5 is a4 detail view showing still another modification.

Fig. 6 is a sectional view taken on the broken line 6 6 of Fig. 5, looking in the direction indicated.

ln the drawings:

'lihe reference numeral 10 indicates a casing for the improved variable condenser of this invention, which casing is preferably made of wood, but which obviously may be made of any other suitable insulating ma-'Ho terial. rllhe casing 10 is rectangular in form, as shown, and is provided at its front with a. metallic plate or the like 12 attached.v to the.' wooden casing '10 by means of suitable wood screws 14:. Screw-.threaded openings 16 are J5 provided in the metal plate 12 and extend into the corresponding front portion of the casing 10, being provided for the reception of machine screws or the like, which are adapted to be fitted into a panel 16, upon the rear face of which the condenser of this invention may be mounted, if desired.

Loosely mounted in conjunction with the bottoniv of the casing 10 and extending across the interior thereof, as shown in Fig. 2, is a block 18 of wood or other suitable insulating material, which is beveled at its` rear end, as shown at 20, in Fig. 1, thereby Vproviding for a pivotal hinged movement ot' said plate 18 about its rear end, and in the 110 casing 10.

As shown in Figs. 1,2 and 3, the metallic foil plates, and dielectric -members of the condenser proper are located between movable blockv 18 and the bottom member of the casing 10, and consist essentially of two sheets of metallic foil, as copper or 'the like, 22, and between them and separating the same a good insulating dielectric 24, as mica or similar material. The metallic foil sheets A22 are attached by non-capacitycement or the like to the upper-end under faces of the .base of the case 10, and. the hingedly movable block 18, respectively.

As shown in the figures, electrical connections are taken off from the foil or plates 22 by means of screws or bolts 26 and'28. The a 'outer 4end of the bolt 26, whi'cli'passes throu h thel base of the container 10, has a'lixe thereto a suitable kuur/led knob orA Y binding post 30 adapted for the convenient connection thereto` of a .conducting wire. The upper condenser plate 22 has similarly connected` theretothe bolt 28, the heads of the bolts 26 and 28 being countersunk in suitable recesses in the member" and 18 respectively, and the metal foil beingl forced down into the countersunk recesses as best shown in F ig.' 3 in order that a good contact will result. The end of the bolt 28 ispro- I vided with a nut 32, by means of which a leaf spring 34 is securely fastened thereto, which leaf spring 34 extends for quite a considerable width 'across the hingedly .movable block member 18, asshown in Fig. 2, and is doubled over upon4 itself vinto a U-sha'pe, as shown in Fig. 1, and has its upper leg spring impelled against the upper `or top member of the casing 10 so as to normally maintain the plate 18'zin its lowermost position and closely pressed'against the. bottom member of the casing 10. The' spring 34 also forms a connecting means "for conducting electricity to and from the upperv foil or plate 22, and contact is made wit said leaf spring 34 fby means of a button or the like36 forming i -the head of a bolt passing through the upper member ofthev casing 10, and .having at its 'bushin is lixedin'an opening inthe front face o the casing 10, and screw-threaded or otherwise attached to 4the metallic plate 12. The bushing maintains the bolt 46 in desired position, which bolt is provided at its outer end with a manually operable adjustin knob 50 or the like.

t'will be seen.that by turning the knob 50 ceases an inward op outward movement of the 22 can be very accurately regulated and determined.

` A'modiication of the inventionI is shown in Fig. 4, wherein two movable blocks 52 and 54 are provided, each one being faced with a metallic foil condenser plate member 56, and having an insulating mica or other dielectric4 means -58therebetween- The blocks are.l

connected by means of a flat leaf s ring 60 fastened thereto b means of the woo 62, and the who e device may be in turn fixed to the back of a panel 64 or the like, by, means of a screw 66. Connecting plugs 68- are provided from the metallic foil members 56, and are provided with binding osts at their outer extremities, as shown. ixed to ythe outer end of the upper block 52 is an L- shaped metallic plate 70, having passing therethrough a screw-threaded bolt 72, wit

a knurled knob 74 on'the end thereof. 'I he inner end of the bolt 72 operates fa ainst the inclined surface of-a bearlng plate 6, which is afiixed to the lower plate 54, so that the distance between the plates 52 and 54 may be very delicately adjusted.

Another modification of the invention is shown in Figs. 5 and 6, whereby moreY prompt e -separation of the plates 10 and 19 ma obtained by means of a cam action, as i lustrated. The cam action is accomplished by means of an egg-shaped cam 78 mounted upon the end of a suitable operating member 80, having a knurled .knob-82 on the outer end thereof, and which member 80 passes through a suitable opening provided 'in the front' face of the casing 10. The cam 78 is adapted to operate against the lower face of a metallic plate or the like 84, lsecurely affixed to the forward end of the`hingedly movable block 18 by means of' a bolt 86, as shown. By this construction a more prom t .angular separation of the plates may be together with a consequently quicker tained, action.

In the referred form of the invention the metallic oil plates are 'approximately .002 of an inch thick, and three mches square, the mica or dielectric being -approximatel from .O01 to .003 inches thick, and of `a. s ghtly larger dimension than that of the foil so as to prevent sho'rting and brush dischar The 'capacit of this size condenser ma conservative y ratedat .0005 micro-fara s.

It will be obvious that herein 'is'provided a very simple and effective form ofvariable condenser, the capacity of which may be changed at will, and which may be adjusted laov the patent granted liereon otherwise than' as necessitated by the prior art;

I claim as my invention:

1. A variable condenser including a plurality of plates, 'a dielectric separating said plates, and means for angularly varying the distance between the plates, said means including an angularly extending portion on e one plate and an adjusting pressure-exerting plates,

.. base of said casing, a binding post in direct means engaging said portion to move the plate to which it is attached.

2. A variable condenser including a plurality of plates, a dielectric separating said plates, and means for angularly varying the distance between the plates, said means including a beveled portion on one end of a plate and adjustable' pressureexerting means engaging said beveled portion.

3. In a variable condenser, a

plates, a portion of said plates being mounted upon a block movable angularly about a fulcrum point, means for angularly moving said block, said means including a screwthreaded adjustment, and an inclined plate upon vthe fulcrumed member upon which said screw-threaded adjustment is adapted to operate.

4. A variable condenser including a casing, a condenser plate upon the inner face of the connection with said condenser plate, an insulatingmember adapted to cooperate with the base of said casing, and movable about a fulcrum point formed by the intersection of the base and one wall of the casing, a metallic foil plate fixed to said movable mem-` ber, and resilient means Jfor maintaining said member in normal position against said base.

5. A variable' condenser including a casing, a condenser plate upon the inner face of the base of said casing, a binding post in direct connection with said condenser plate,

an insulating member adapted to cooperate y plurality of a dielectric means separating said with the `base of said casing, and movable about a fulcrum point formed by the intersection ot the base and one Wall of the casing, a metallic foil plate fixed to said movable member, resilient means for maintaining said member in normal position against said base, and manually operated means for varying the angular relation between said movable member and the -base of the casing.

6. A variable condenser including a casing, a condenser plate upon the inner face of the base of said casing, a binding post in direct connection with said condenser plate, an insulating member adapted to cooperate with the base of said casing, and movable about a fulcrum point formed by the intersection ot the base and one wall of the casing, a metallic foil plate fixed to said movable member, resilient means for maintaining said member in normal position against said base, and manually operated means for varying the an ar relation between said movable mem r and the base of the casing, said means including a screwthreaded bolt passing through one end wall of the casing, and a beveled plate on the end of said movable member against which the end of said screw-threaded bolt is adapted to operate. e

7. A variable condenser including a casing, a condenser plate upon the inner face of the base of said casing, a binding post in direct connection with said condenser plate, an insulating member adapted to cooperate with the base of said casing, and movableabout a fulcrum point formed by the intersection of the base and one wall of the casing, a metallic foil plate fixed to said movable member, resilient means for maintaining said member in normal position against said base, an additional binding post upon the top of said casing, and a connection from said blnding post to the movable plate of the condenser, said connection including the aforesaid resilient means.

8. A variable condenser including a plurality of plates, a dielectric separating said plates, means for angularly varying the distancepbetween the plates, and resilient means for normally maintaining the plates in full capacity relation, said resilient means forming partei the electrical connection to said plates.

In testimony whereof I aiiix my signature.

GASIMIR S. OHiERPECK. 

